Roller mill with rotating grinding vessel

ABSTRACT

A roller mill having a rotatable grinding vessel with a drive shaft for the grinding vessel connected to a transmission where the connection between shaft and vessel is non-positive or interruped.

United States Patent Bacharach [451 Apr. 18, 1972 1 ROLLER MILL WITH ROTATING [56] References Cited GRINDING VESSEL v UNITED STATES PATENTS [72] Bachamh' Kaiseslamem' 2 51s 42s 8/1950 McMurray 146/67 x many 3,540,234 11/1970 Raymond ..146/68 A x [73] Assignee: Gebr, Pfeifier Barbamssawerke AC, 3,550,657 12/ 1970 swanl fie 146/68 A Kajserslautem am Pfalz, Germany 3,076,489 2/ 1 963 Schmidt et a1 146/ l 82 [22] Filed: June 12, 1970 21 APPL N 45,35 Primary Examiner-Robert L. Spruill Attorney-Robert H. Jacob 64/9 R, 14 [30] Foreign Apphcatlon Prlomy Data June 12, 1969 Germany ..P 19 29 912.8 1 1 ABSTRACT A roller mill having a rotatable grinding vessel with a drive [5 2] U.S. Cl ..241/103, 241/1 17, 241/173, h f for the grinding vessel connected to a transmission where 4/ R the connection between shaft and vessel is non-positive or in- [51] Int. Cl. ..B02c 15/00, B020 4/42 terruped. v [58] Field ofSearch ..24l/l03,104, 117-121,

241/173, 176, 10 S; 34/121; 259/57, 81; 146/67A; 2 Claims, 2 Drawing Figures 7 s 2 s e l 1 l I I l 2o PATENTEDAPR 18 m2 3,656,695

INVEN TOR. Ottmar BACHA RACH l ROLLER MILL WI'I'I-I ROTATING GRINDING VFSSEL BACKGROUND OF THE INVENTION The invention relates to shaft driven roller grinding mills. More in particular, the invention concerns a roller. mill with a rotary grinding vessel where the grinding vessel is put in rotation by drive means in the base of the mill with an intermediate transmission. Mills of this type, when overly loaded or filled are prone to oscillate if they are improperly operated. This results from the fact that the mass of the grinding vessel and a shaft disposed between the transmission and the vessel form a system as a torsion spring in which rotary oscillations can develop. Due to the grinding rollers, possibly influenced by the gears of the transmission, it is possible that oscillations develop in a resonance range that produce large forces and result under certain conditions in damage to the transmission.

Acceleration measurements undertaken during operation of such mills have led to the discovery that the conditions described above appear to exist.

SUMMARY OF THE INVENTION It is, therefore, an object of the invention to find meansand ways that make it possible to prevent this resonance in order to protect essential parts of the mill against damage. Thus the course toward a satisfactory solution leads to finding a force the former uninterrupted connection that resulted in the oscillatory system is changed in a manner that it is no longer possible for an uninterrupted oscillatory system to develop. Thus an interruption is found for the uninterrupted connection.

ln particular the interrupted connection is chosen so that the flange of the transmission is arranged rotatably upon the end shaft and is no longer keyed to the shaft coming from the transmission as heretofore. The transmission shaft is longed or extended upwardly and is one-sidedly coupled with the grinding vessel, as seen in the direction of rotation. At any rate, the oscillatory system that existed heretofore is interrupted, while the radial guidance of the grinding vessel is maintained.

pro-

. BRIEF DESCRIPTION OF THE DRAWINGS Further features of the invention and details of the advantages obtained thereby will become apparent from the following description of an embodiment of the subject of the invention schematically illustrated in the drawings in which,

FIG. 1 is a section taken along line l-I in FIG. 2, and

FIG. 2 is a plan view taken along line II-II in FIG. 1.

From the transmission 1 of a grinding roller mill a drive shaft 2 for the grinding vessel 3 extends vertically upwardly.

The flange 4 of the transmission is rotatably arranged in the embodiment chosen as an example. The drive shaft 2 which extends from the transmission 1 is prolonged upwardly and equipped with a head member 5 which has radially outwardly extending keys 6 or the like. These keys 6 rest against driven members having contact surfaces 7 of the grinding vessel base structure 8 as seen in the direction of rotation. The shaft 2 is supported at its lower end and below flange 4' by bearings 2a and 2b, respectively, and a sliding-bearing 4a is interposed between flange 4 and the top of the transmission.

Thus there is no longer a positive connection between the mass of the vessel 3 and its associated parts on the one hand and the transmission and its parts on the other hand, but merely an open or interrupted force transmitting connection. The oscillatory system in which rotational oscillations were formerly able to develop is interrupted. Of course, the radial guidance of the grinding vesselis maintained.

Having now escnbed my invention with reference to the embodiment illustrated, what I desire to protect by letters patent of the United States is set forth in the appended claims.

I claim:

1. Roller mill having a rotatable grinding vessel having a base supported above a transmission, a sliding bearing intermediate the base of said vessel and said transmission, a shaft extending intermediate said transmission and said grinding vessel centrally of said grinding vessel base and interrupted force transmitting means intermediate the upper end of said shaft and said grinding vessel base, said interrupted force transmitting means comprising a driving key or the like on said shaft and a driven member having a contact surface on said grinding vessel'base.

2. Roller mill with rotatable grinding vessel in accordance with claim 1 comprising a plurality of driving keys or the like and a plurality of corresponding driven members with spaces between said keys and proximate contact surfaces. 

1. Roller mill having a rotatable grinding vessel having a base supported above a transmission, a sliding bearing intermediate the base of said vessel and said transmission, a shaft extending intermediate said transmission and said grinding vessel centrally of said grinding vessel base and interrupted force transmitting means intermediate the upper end of said shaft and said grinding vessel base, said interrupted force transmitting means comprising a driving key or the like on said shaft and a driven member having a contact surface on said grinding vessel base.
 2. Roller mill with rotatable grinding vessel in accordance with claim 1 comprising a plurality of driving keys or the like and a plurality of corresponding driven members with spaces between said keys and proximate contact surfaces. 